Today news broke that the mystery substance was a mixture of hand cleaner, water, and Tomcat mice poison. And now, according to the New York Times, the FBI has taken into custody one man whom they believe to be the culprit. The authorities have yet to release his name to the public.

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The dangerous concoction was sprayed onto the self-serve food bars and some stacks of produce. But the most chilling detail is that he reportedly targeted multiple grocery stores—not just one Whole Foods in Ann Arbor, but a location of Meijer and potentially other supermarkets in Flint, officials say.

Whole Foods in Ann Arbor responded quickly, removing and replacing all of the the salad and hot food bar trays immediately. "All food was thrown out and the store team thoroughly cleaned and sanitized all food stations, equipment and serving utensils before restocking with fresh items," the company's public relations representatives, Allison Phelps, told MLive. And luckily, no illnesses have been reported.

The man in question could face felony charges for intentional adulteration of food in interstate commerce, among other charges—though his motive remains unknown.